In electronics a NOT gate is more commonly called an inverter. The circle on the symbol is called a bubble, and is used in logic diagrams to indicate a logic negation between the external logic state and the internal logic state (1 to 0 or vice versa).
A weather watch, on the other hand, typically refers to an alert issued to indicate that conditions are favorable for the development of dangerous weather patterns, although the dangerous weather conditions themselves are not currently present.
A Heat Advisory may be issued for lower criteria if it is early in the season or during a multi-day heat wave. Fire Weather Watch. A Fire Weather Watch is issued to alert fire officials and firefighters of potentially dangerous fire weather conditions within the next 24 to 36 hours.